Steve Cunningham has accused Tyson Fury of using an illegal manoeuvre to knock him out during their heavyweight fight at Madison Square Garden.

In a heated exchange with American boxing radio talk show host Rufus Defibaugh, the two-time cruiserweight world champion hit back at claims he was "riding the gravy train" by fighting Fury, and admitted that the experience had left him frustrated with the sport.

Cunningham floored Fury in the second round with an overarm left, just the second time in his professional career that the 24-year-old has been left on the canvas.

"It is not in the f*****g rules," Cunningham told ATG Radio after ripping in to Defibaugh, who lost the only professional fight of his abortive career in 1985.

"Tyson Fury performed illegal manoeuvres to knock me out. He held me with his forearm. He pushed me in the corner twice - which is illegal - and then he pushed me with his forearm, cocked my head to the left and threw a right hook."

On the back of his controversial split decision defeat by Tomasz Adamek in December, Cunningham admitted that this latest episode had led him to question his place in the sport.

"You caught me at the wrong time," Cunningham added. "I'm p****d at the moment and I'm frustrated with this entire industry."

Cunningham has demanded a rematch against Fury, but the Briton's coach and uncle Peter Fury insists it will not happen.